The invention relates to electronic postage meters and to electronic postage metering accounting units designed for operation in conjunction with a users' computer and printer. As used herein the term electronic postage meter also refers to other similar meters, such as parcel registers and tax meters, which dispense and account for value.
Electronic postage meters are known and described for example in U.S. Pat. No. 3,978,457 to Check et al. Electronic postage meters which utilize the customer's computer and printer are described for example, in copending application Ser. No. 724,372 of Muller filed Apr. 17, 1985 and in a copending application by R. Sansone et al. entitled POSTAGE AND MAILING INFORMATION APPLYING SYSTEM filed concurrently herewith.
In postage meters, the need for security is absolute. The reason for the absolute security requirement is that a postage meter is printing value, and unless security measures are taken, one would be able to print unauthorized postage, thereby defrauding the U.S. Postal Service. Most of the security measures taken are of a physical nature, but recently there have been suggestions for use of encryption to ensure that a postage indicia is valid.
In these meters, however, the security efforts have been directed mainly to preventing fraud on the Postal Service. There has been no consistent attempt to provide security for the customer who is authorized to use the postage meter to enable him to prevent unauthorized access for the use of the postage meter except by use of a lock and key to turn on the meter. Typically anyone who has physical access to the operating postage meter can meter postage for personal or unauthorized use at the expense of the authorized customer who has paid for the postage.